When you plan to implement an Exchange Hybrid Configuration between your on-premises Exchange Organization and Exchange online you have to choose between two variants and five operating modes. It is not as complicated as it sounds.
I have written a blog post about the different options available.
The post is published in ENow's ESE blog.
Enjoy.
Once upon a time at an Exchange Conference near you, a member of the Exchange Product Group (PG) announced that the very last Exchange Server will go away when having an active Exchange hybrid setup.
This was a hot topic for discussions at the Microsoft Exchange Conferences (MEC, @IamMEC) in 2012 and 2014, already. Since then the Exchange PG came up with a number of reasons why this is not possible. The question on when we will finally be able to remove the very last Exchange Server from the on-premises Exchange organization was asked every year at the Ignite Conference.
Currently, the supported scenario for hybrid configurations between your on-premises Exchange organization and Exchange Online requires that you keep the last Exchange Server for creating, and managing Exchange related objects, even if those objects are located in Exchange Online.
The following diagram illustrates the current requirements:
In the past, there was communication on certain interim solutions that were supposed to support you in removing the last Exchange Server from your Exchange organization. Such interim solutions were:
At Ignite those solutions even made it into the official session catalog:
All those interim solutions leave your on-premises Exchange organization and the Active Directory configuration in an uncomfortable twilight-zone. It was still something that worked somehow, but you knew it was officially not supported, and the secure and stable operation of the hybrid configuration was at risk.
But wait...
Removing the last Exchange Server is supported! (at least when all components are released)
The new approach for managing your Exchange Online tenancy after migrating your on-premises Exchange organization to Exchange Online does not require an on-premises Exchange Server.
The new mode of operation reduces your on-premises requirements to:
The following diagram illustrates the new modern Exchange Online Management experience:
Simply you remove the requirement to use on-premises Exchange Server to write to your on-premises Active Directory. Instead, Azure AD Connect uses a new synchronization capability to handle the new Exchange Management experience in the AAD Connect MetaVerse. The on-premises AD-connector writes the changes to Active Directory which keeps the Active Directory up-to-date for all other on-premises solutions that require identities to have a proper state.
You execute all Exchange-related actions using the new Exchange Online Management PowerShell module, or, if needed, the new Modern Exchange Admin Center (EAC, which was announced at Ignite 2019.
Before you uninstall the last Exchange Server from your on-premises Exchange organization, ensure that you
PS C:\> Get-WindowsFeature Display Name Name Install State ------------ ---- ------------- [ ] Active Directory Certificate Services AD-Certificate Available [ ] Certification Authority ADCS-Cert-Authority Available [ ] Certificate Enrollment Policy Web Service ADCS-Enroll-Web-Pol Available [ ] Certificate Enrollment Web Service ADCS-Enroll-Web-Svc Available [ ] Certification Authority Web Enrollment ADCS-Web-Enrollment Available [ ] Network Device Enrollment Service ADCS-Device-Enrollment Available [ ] Online Responder ADCS-Online-Cert Available [ ] Active Directory Domain Services AD-Domain-Services Available [ ] Active Directory Federation Services ADFS-Federation Available [ ] Active Directory Lightweight Directory Services ADLDS Available [ ] Active Directory Rights Management Services ADRMS Available [ ] Active Directory Rights Management Server ADRMS-Server Available [ ] Identity Federation Support ADRMS-Identity Available [ ] Device Health Attestation DeviceHealthAttestat... Available [ ] DHCP Server DHCP Available [ ] DNS Server DNS Available [ ] Exchange Online Remote Features EXORemote Available [ ] Fax Server Fax Available [X] File and Storage Services FileAndStorage-Services Installed [X] File and iSCSI Services File-Services Installed [X] File Server FS-FileServer Installed [ ] BranchCache for Network Files FS-BranchCache Available [...]
PS C:\> Install-WindowsFeature -Name EXORemote Display Name Name Install State ------------ ---- ------------- [ ] Active Directory Certificate Services AD-Certificate Available [ ] Certification Authority ADCS-Cert-Authority Available [ ] Certificate Enrollment Policy Web Service ADCS-Enroll-Web-Pol Available [ ] Certificate Enrollment Web Service ADCS-Enroll-Web-Svc Available [ ] Certification Authority Web Enrollment ADCS-Web-Enrollment Available [ ] Network Device Enrollment Service ADCS-Device-Enrollment Available [ ] Online Responder ADCS-Online-Cert Available [ ] Active Directory Domain Services AD-Domain-Services Available [ ] Active Directory Federation Services ADFS-Federation Available [ ] Active Directory Lightweight Directory Services ADLDS Available [ ] Active Directory Rights Management Services ADRMS Available [ ] Active Directory Rights Management Server ADRMS-Server Available [ ] Identity Federation Support ADRMS-Identity Available [ ] Device Health Attestation DeviceHealthAttestat... Available [ ] DHCP Server DHCP Available [ ] DNS Server DNS Available [X] Exchange Online Remote Features EXORemote Installed [ ] Fax Server Fax Available [X] File and Storage Services FileAndStorage-Services Installed [X] File and iSCSI Services File-Services Installed [X] File Server FS-FileServer Installed [ ] BranchCache for Network Files FS-BranchCache Available [...]
Even though not explicitly stated, you should restart the server after installing the Windows feature.
As part of the next AAD Connect synchronization cycle, the magic happens.
Verify that you can edit the Exchange related attributes of synchronized Active Directory objects in Exchange Online or Azure AD before you remove your last Exchange Server.
Whey ready to uninstall the last Exchange Server you must use the following command line parameters to remove the server as intended. Otherwise, you'll leave the Exchange organization in an inchoate state. Ensure that you use an administrative PowerShell session.
./Setup.exe /mode:uninstall /SwitchToMEMA /IAcceptExchangeOnlineLicenseTerms
Normally, you do not have to accept license terms when uninstalling Exchange Server, but in this case, you have to accept the Exchange Online license terms.
Enjoy the modern experience and management options of Exchange Online!
Exchange Conferences
Exchange Server 2016 introduced the PowerShell cmdlet Get-MailboxServerRedundancy. This cmdlet helps you plan and prepare for Exchange Server maintenance by querying the current maintenance readiness of the database availability group (DAG).
Interestingly, there is no PowerShell help available for this vital cmdlet. Microsoft Docs or Exchange Management Shell's Get-Help provide any valuable information.
When querying a DAG about the server redundancy status, the cmdlet's default output provides you with the essential information.
The default output contains information about:
This example shows the Get-MailboxServerRedundancy output of a six server DAG, before activating maintenance mode for server LOCEXS06.
Get-MailboxServerRedundancy -DatabaseAvailabilityGroup EXDAG01 Identity IsServerFound IsInMainten RepairUrgency SafeForMaintenance HealthInfoLastUpdateTime InAD ance -------- ------------- ----------- ------------- ------------------ ------------------------ LOCEXS01 True False Prohibited False 17.02.2020 09:10:11 LOCEXS02 True False Normal True 17.02.2020 09:10:11 LOCEXS03 True False Normal True 17.02.2020 09:10:11 LOCEXS06 True False Normal True 17.02.2020 09:10:11 LOCEXS05 True False Normal True 17.02.2020 09:10:11 LOCEXS04 True False Prohibited False 17.02.2020 09:10:11
As Exchange Administrator, you are most interested in the information displayed in columns RepairUrgency and SafeForMaintenance.
As you can see in this screenshot, no server is in maintenance mode. Servers S01 and S04 have a RepairUrgency state of Prohibited, and a SafeForMaintenance state of False. The latter tells us that we cannot activate maintenance mode for servers safely without risking mailbox database redundancy.
What is the reason for this? Let's have a look.
You can use the same cmdlet to query detailed information for each member server of the DAG. The default output for a single server does not provide any additional information on the server status.
Get-MailboxServerRedundancy -DatabaseAvailabilityGroup EXDAG01 -Identity LOCEXS01 Identity IsServerFound IsInMainten RepairUrgency SafeForMaintenance HealthInfoLastUpdateTime InAD ance -------- ------------- ----------- ------------- ------------------ ------------------------ LOCEXS01 True False Prohibited False 17.02.2020 09:11:11
Because we cannot activate maintenance mode for server LOCEXS01 safely, we are interested in identifying which redundancy state is responsible.
You can find this information by displaying the detailed server information.
Use the Format-List, or short FL, cmdlet to display the Get-MailboxServerRedundancy cmdlet output as a formatted list.
Get-MailboxServerRedundancy -DatabaseAvailabilityGroup EXDAG01 -Identity LOCEXS01 | FL RunspaceId : 70d82f8d-e6ca-4bfc-863f-11300a9784ff Identity : LOCEXS01 IsServerFoundInAD : True IsInMaintenance : False RepairUrgency : Prohibited SafeForMaintenance : False ServerContactedFqdn : LOCEXS04.VARUNAGROUP.DE HealthInfoCreateTime : 15.06.2018 15:16:19 HealthInfoLastUpdateTime : 17.02.2020 09:11:11 ServerFoundInAD : CurrentState: Active; LastActiveTransition: 15.06.2018 15:22:16; LastInactiveTransition: InMaintenance : CurrentState: Inactive; LastActiveTransition: 17.01.2020 09:07:02; LastInactiveTransition: 17.01.2020 10:42:02 AutoActivationPolicyBlocked : CurrentState: Inactive; LastActiveTransition: 09.01.2020 10:14:50; LastInactiveTransition: 09.01.2020 11:00:51 ActivationDisabledAndMoveNow : CurrentState: Inactive; LastActiveTransition: ; LastInactiveTransition: 15.06.2018 15:22:16 HighAvailabilityComponentStateOffline : CurrentState: Inactive; LastActiveTransition: 17.01.2020 09:07:02; LastInactiveTransition: 17.01.2020 10:42:02 CriticalForMaintainingAvailability : CurrentState: Inactive; LastActiveTransition: 31.01.2020 16:52:49; LastInactiveTransition: 31.01.2020 16:56:49 CriticalForMaintainingRedundancy : CurrentState: Active; LastActiveTransition: 29.01.2020 11:43:06; LastInactiveTransition: 29.01.2020 11:42:06 PotentiallyCriticalForMaintainingRedundancy : CurrentState: Active; LastActiveTransition: 01.02.2020 05:49:37; LastInactiveTransition: CriticalForRestoringAvailability : CurrentState: Inactive; LastActiveTransition: 06.05.2019 09:16:36; LastInactiveTransition: 06.05.2019 09:20:36 CriticalForRestoringRedundancy : CurrentState: Inactive; LastActiveTransition: 29.01.2020 11:42:06; LastInactiveTransition: 29.01.2020 11:43:06 HighForRestoringAvailability : CurrentState: Inactive; LastActiveTransition: 29.01.2020 11:42:06; LastInactiveTransition: 29.01.2020 11:43:06 HighForRestoringRedundancy : CurrentState: Inactive; LastActiveTransition: 10.02.2020 09:05:02; LastInactiveTransition: 10.02.2020 09:06:02 IsSafeForMaintenance : CurrentState: Inactive; LastActiveTransition: 03.11.2019 09:42:35; LastInactiveTransition: 12.11.2019 06:29:58 IsValid : True ObjectState : Unchanged
The lines 24-27 show the information we want to know. Both, the CriticalForMaintainingRedundancy and PotentiallyCriticalForMaintainingRedundancy parameters have a CurrentState value of Active. The Primary Activation Manager (PAM) considers the server availability critical to provide redundant availability of the database copies hosted by this server.
Each of state-parameter shows three pieces of information:
But there is still the bothering question of why are two of the six servers not safe for activating maintenance?
The reason is simple. The mailbox databases mounted by the member servers of the DAG have a different number of database copies. This configuration is due to data storage capacity constraints.
The mailbox databases storing primary user mailboxes use four database copies per database. Those copies are evenly distributed across all six mailbox servers. Mailbox database storing online archive mailboxes use three copies per database. This database copy layout allows for safely activating server maintenance for one server at a time without risk to database redundancy.
The servers LOCEXS01 and LOCEXS04 hold mailbox databases with just two copies per configured database. Placing one of those two servers into maintenance mode reduces the database availability for these mailbox databases to one. Therefore, PAM informs us that database redundancy is at risk when activating maintenance for those two servers.
This example shows the member server redundancy state while LOCEXS06 is in maintenance. The reason for monthly maintenance for installing Windows updates.
Maintenance was activated using the StartDagServerMaintenance.ps1 PowerShell script.
Get-MailboxServerRedundancy -DatabaseAvailabilityGroup indag01 Identity IsServerFound IsInMainten RepairUrgency SafeForMaintenance HealthInfoLastUpdateTime InAD ance -------- ------------- ----------- ------------- ------------------ ------------------------ LOCEXS01 True False Prohibited False 17.02.2020 11:04:12 LOCEXS02 True False Normal True 17.02.2020 11:04:12 LOCEXS03 True False Prohibited False 17.02.2020 11:04:12 LOCEXS06 True True High True 17.02.2020 11:04:12 LOCEXS05 True False Prohibited False 17.02.2020 11:04:12 LOCEXS04 True False Prohibited False 17.02.2020 11:04:12
Having a single server in maintenance has a significant impact on all other servers in the DAG. The servers LOCEXS03 and LOCEXS05 are not safe for maintenance as well. Activating maintenance for those two servers would affect the database redundancy for the databases hosted by those two servers.
After completing all maintenance tasks, e.g., installing Windows Updates or a new Exchange Server Cumulative Update, you end server maintenance using the PowerShell script StopDagServerMaintenance.ps1.
We query the server redundancy state again.
Get-MailboxServerRedundancy -DatabaseAvailabilityGroup indag01 Identity IsServerFound IsInMainten RepairUrgency SafeForMaintenance HealthInfoLastUpdateTime InAD ance -------- ------------- ----------- ------------- ------------------ ------------------------ LOCEXS01 True False Prohibited False 17.02.2020 11:23:12 LOCEXS02 True False Normal True 17.02.2020 11:23:12 LOCEXS03 True False Normal True 17.02.2020 11:23:12 LOCEXS06 True False High True 17.02.2020 11:23:12 LOCEXS05 True False Normal True 17.02.2020 11:23:12 LOCEXS04 True False Prohibited False 17.02.2020 11:23:12
Server LOCEXS06 is not in maintenance, but the RepairUrgency state is High. The local Exchange Server replication engine is still busy replicating and processing log files, and updating the search indices. When CopyQueueLength and ReplayQueueLength are back to 0, and ContentIndexStates are back to Healthy, the RepairUrgency switches to Normal.
You receive an error message when activating maintenance for an Exchange Server not safe for maintenance using StartDagServerMaintenance.ps1 -serverName [SERVER] In this case, you must use:
.\StartDagServerMaintenance.ps1 -serverName SERVERNAME -overrideMinimumTwoCopies:$true
Enjoy Exchange Server!
Azure AD Pass-through authentication (PTA) recommends that you run at least three authentication agents to provide high availability for authentication.
When you download and install the PTA agent, registering the PTA agent to Azure AD might fail. This happens most of the time when the network connectivity to Azure AD requires the use of a proxy server. In such a network setup you normally encounter configuration errors only, if the proxy server is misconfigured or the Internet Explorer zone configuration is missing required entries for trusted sites.
When you encounter an error during installation and registration of the dedicated PTA agent I recommend to separate these two steps. You need the credentials of an Azure AD account that is a member of the Global Administrator management group.
AADConnectAuthAgentSetup.exe REGISTERCONNECTOR="false" /q
# navigate to the default installation location cd "C:\Program Files\Microsoft Azure AD Connect Authentication Agent" # enter the global admin credentials $cred = Get-Credential # register the PTA agent using the RegisterConnector.ps1 script # multiline example .\RegisterConnector.ps1 ` -ModulePath "C:\Program Files\Microsoft Azure AD Connect Authentication Agent\Modules\" ` -ModuleName "PassthroughAuthPSModule" ` -AuthenticationMode Credentials ` -UserCredentials $cred ` -Feature PassthroughAuthentication # single line example .\RegisterConnector.ps1 -ModulePath "C:\Program Files\Microsoft Azure AD Connect Authentication Agent\Modules\" -ModuleName "PassthroughAuthPSModule" -AuthenticationMode Credentials -UserCredentials $cred -Feature PassthroughAuthentication
The Azure AD Pass-through agent Quickstart documentation has an example for automating the installation of the PTA agent as part of a server provisioning process. The current example references the wrong PowerShell module named AppProxyPSModule. The most recent release of the PTA agent does not contain a PowerShell module by that name. Use the PowerShell module PassthroughAuthPSModule, as shown in the PowerShell example shown above.
Enjoy Azure AD!
This script reads Exchange Organization data and creates a single Microsoft Word document. A later version will support exporting to an Html file.
The script requires an Exchange Management Shell for Exchange Server 2016 or newer. Older EMS versions are not tested.
A locally installed version of Word is required, as plain Html export is not available, yet.
The default file name is 'Exchange-Org-Report [TIMESTAMP].docx'.
Most of the script requires only Exchange admin read-only access for the Exchange organization. Querying address list information requires a membership in the RBAC role "Address Lists".
The script queries hardware information from the Exchange server systems and requires local administrator access to the computer systems.
# Example 1 # Create a Word report for the local Exchange Organization using # the default values defined on the parameters section of the PowerShell script. .\Get-ExchangeOrganizationReport.ps1 -ViewEntireForest:$true # Example 2 # Create a Microsoft Word report for the local Exchange Organization with # a verbose output to the current PowerShell session. .\Get-ExchangeOrganizationReport.ps1 -Verbose
The script is based on the ADDS_Inventory.ps1 PowerScript by Carl Webster: https://github.com/CarlWebster/ActiveDirectory